US20090235733A1 - Metal disk discrimination apparatus - Google Patents

Metal disk discrimination apparatus Download PDF

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Publication number
US20090235733A1
US20090235733A1 US12/361,706 US36170609A US2009235733A1 US 20090235733 A1 US20090235733 A1 US 20090235733A1 US 36170609 A US36170609 A US 36170609A US 2009235733 A1 US2009235733 A1 US 2009235733A1
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US
United States
Prior art keywords
metal disk
leg portions
face
target metal
magnetic sensors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/361,706
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English (en)
Inventor
Takehiro Hato
Toshikatsu Akiba
Kazumi Kotani
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Toshiba TEC Corp
Original Assignee
Toshiba Corp
Toshiba TEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Toshiba TEC Corp filed Critical Toshiba Corp
Assigned to TOSHIBA TEC KABUSHIKI KAISHA, KABUSHIKI KAISHA TOSHIBA reassignment TOSHIBA TEC KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AKIBA, TOSHIKATSU, HATO, TAKEHIRO, KOTANI, KAZUMI
Publication of US20090235733A1 publication Critical patent/US20090235733A1/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D5/00—Testing specially adapted to determine the identity or genuineness of coins, e.g. for segregating coins which are unacceptable or alien to a currency
    • G07D5/08—Testing the magnetic or electric properties
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D5/00—Testing specially adapted to determine the identity or genuineness of coins, e.g. for segregating coins which are unacceptable or alien to a currency
    • G07D5/005—Testing the surface pattern, e.g. relief

Definitions

  • One aspect of the present invention relates to a discrimination apparatus which discriminates between genuineness and counterfeit, kinds, etc. of metal disks such as coins. Particularly, it relates to a discrimination apparatus which is improved in sensitivity and accuracy for detecting a surface shape or an edge of each metal disk.
  • a coin change machine, an automatic vending machine or the like in a point of sales (POS) registration system is equipped with a coin discrimination apparatus which discriminates between genuineness and counterfeit of inserted coins and discriminates between kinds of the coins.
  • POS point of sales
  • metal disks such as medals used in a game arcade or the like may need to be discriminated in the same manner as the coins.
  • Magnetic sensors using coils and cores are used as mainstream sensors used for discriminating coins in a coin change machine, an automatic vending machine, etc.
  • Kinds of magnetic sensors are used for detecting materials, outer diameters, thicknesses, etc. of coins so that discrimination is performed based on these pieces of information.
  • the coils are excited to emit magnetic flux so that discrimination is performed based on the difference between electrical characteristics which appear in sensor signals when coins pass through the magnetic flux.
  • JP-B-3891101 has a pair of two-legged magnetic sensors: one sensor is disposed along one side of a coin passageway so that respective end faces of the legs become parallel to a central surface of the coin passageway; and the other sensor is disposed on the opposite side of the coin passageway so as to be symmetrical to the one sensor with interposition of the coin passageway.
  • the end face of each leg is shaped like a rectangle.
  • the pair of two-legged magnetic sensors are disposed so that long sides of each rectangle are perpendicular to the direction of movement of a coin, and that the long sides facing each other are arranged at a distance so as to be parallel to each other.
  • Coils are excited so that the two legs of each sensor emit magnetic fluxes with opposite magnetic polarities whereas magnetic pole surfaces facing each other with interposition of the coin passageway have the same polarity.
  • the magnetic fluxes are refluxed between the two legs so that the magnitude of leakage magnetic flux emitted from other places than the long sides can be ignored compared with the magnitude of principal magnetic flux flowing between the long sides.
  • a coin discrimination apparatus is configured.
  • a metal disk discrimination apparatus including: two magnetic sensors configured to sandwich a target metal disk and disposed in positions symmetrical to each other with respect to the target metal disk, each of the two magnetic sensors including: a two-legged core having: two leg portions disposed opposing to a face of the target metal disk with an interval between the two leg portions along a movement direction, the movement direction in which the two magnetic sensors move relatively with respect to the target metal disk along a direction parallel to faces of the target metal disk, the two leg portions exhibiting magnetic polarities opposite to each other, each of the two leg portions having an end face facing the target metal disk, and a connection portion disposed distant from the target metal disk and magnetically connecting the two leg portions; and two coils respectively wound on the two leg portions; an oscillation circuit configured to pass an alternating current through each of the two coils; and a signal processing unit configured to determine a shape of the target metal disk by comparing an output signal of the two magnetic sensors with a reference value, the output signal corresponding to a change
  • FIG. 1 is an exemplary perspective view showing an embodiment of a metal disk discrimination apparatus according to the invention
  • FIG. 2 is an exemplary plan view of the metal disk discrimination apparatus shown in FIG. 1 ;
  • FIG. 3 is an exemplary vertical sectional view of the metal disk discrimination apparatus taken along the line III-III in FIG. 2 ;
  • FIG. 4 is an exemplary side view viewed from an arrow IV in FIG. 2 ;
  • FIG. 5 is an exemplary bottom view viewed from the line V-V in FIG. 2 ;
  • FIG. 6 is an exemplary circuit diagram showing an embodiment of the metal disk discrimination apparatus according to the invention.
  • FIG. 7 is an exemplary bottom view showing magnetic lines of flux in the bottom view of FIG. 5 ;
  • FIGS. 8A to 8C are exemplary bottom views showing shapes of end portions of leg portions of various magnetic sensors
  • FIG. 9 is a graph showing an example of specific experimental data for obtaining a graph shown in FIG. 10 ;
  • FIG. 10 is an exemplary graph showing the difference between sensor outputs according to shapes of the end portions of the leg portions of the various magnetic sensors
  • FIG. 11 is an exemplary bottom view like FIG. 5 , showing a modification of the shape of each of the leg portions of the magnetic sensors in the metal disk discrimination apparatus according to the invention
  • FIG. 12 is an exemplary bottom view like FIG. 5 , showing another modification of the shape of each of the leg portions of the magnetic sensors in the metal disk discrimination apparatus according to the invention
  • FIG. 13 is an exemplary bottom view like FIG. 5 , showing a further modification of the shape of each of the leg portions of the magnetic sensors in the metal disk discrimination apparatus according to the invention
  • FIG. 14 is an exemplary bottom view showing a relationship between an edge of a metal disk and one of the end portions of the leg portions of the magnetic sensors in the metal disk discrimination apparatus when the leg portion is shaped like a rectangle;
  • FIG. 15 is an exemplary vertical sectional view like FIG. 3 , showing a modification of the shape of each magnetic sensor in the metal disk discrimination apparatus according to the invention.
  • FIG. 16 is an exemplary vertical sectional view like FIG. 3 , showing another modification of the shape of each magnetic sensor in the metal disk discrimination apparatus according to the invention.
  • FIG. 1 is a perspective view showing an embodiment of the metal disk discrimination apparatus according to the invention.
  • FIG. 2 is a plan view of the metal disk discrimination apparatus shown in FIG. 1 .
  • FIG. 3 is a vertical sectional view taken along the line III-III in FIG. 2 .
  • FIG. 4 is a side view from the arrow IV in FIG. 2 .
  • FIG. 5 is a bottom view from the line V-V in FIG. 3 .
  • the metal disk discrimination apparatus has a disk passageway 2 , a first magnetic sensor 10 , and a second magnetic sensor 20 .
  • Metal disks 3 such as coins are one by one moved straight on the disk passageway 2 in a direction 1 of movement of a surface of the disk passageway 2 .
  • the first and second magnetic sensors 10 and 20 are disposed in positions where each metal disk 3 is put between the first and second magnetic sensors 10 and 20 when the metal disk 3 passes through the disk passageway 2 .
  • the first magnetic sensor 10 has a two-legged core 11 , and coils 16 and 17 .
  • the two-legged core 11 is shaped like a U figure in vertical section.
  • the two-legged core 11 has two leg portions 12 and 13 , and a connection portion 18 by which the two leg portions 12 and 13 are connected to each other.
  • the two leg portions 12 and 13 are arranged side by side in the movement direction 1 of the metal disk 3 so that end faces 14 and 15 of the two leg portions 12 and 13 face on one disk surface 4 of the metal disk 3 .
  • the connection portion 18 connects the two leg portions 12 and 13 to each other on a side distant from the respective end faces 14 and 15 of the two leg portions 12 and 13 .
  • the leg portions 12 and 13 are wound with the coils 16 and 17 respectively.
  • the end faces 14 and 15 of the respective leg portions 12 and 13 have magnetic polarities opposite to each other.
  • the second magnetic sensor 20 has the same shape and configuration as the first magnetic sensor 10 .
  • the second magnetic sensor 20 is disposed so as to be symmetrical to the first magnetic sensor 10 with respect to the surface of the disk passageway 2 through which the metal disk 3 passes. That is, the second magnetic sensor 20 has a two-legged core 21 , and coils 26 and 27 .
  • the two-legged core 21 has two leg portions 22 and 23 , and a connection portion 28 by which the two leg portions 22 and 23 are connected to each other.
  • the two leg portions 22 and 23 are arranged side by side in the movement direction 1 of the metal disk 3 so that end faces 24 and 25 of the two leg portions 22 and 23 face on the other disk surface 4 a of the disk metal 3 opposite to the disk surface 4 .
  • connection portion 28 connects the two leg portions 22 and 23 to each other on a side distant from the respective end faces 24 and 25 of the two leg portions 22 and 23 .
  • the two leg portions 22 and 23 are wound with the coils 26 and 27 respectively.
  • the end faces 24 and 25 of the two leg portions 22 and 23 have magnetic polarities opposite to each other.
  • leg portions 12 and 22 of the pair of two-legged cores 11 and 21 opposite to each other with interposition of the metal disk 3 have the same magnetic polarity.
  • the leg portions 13 and 23 of the pair of two-legged cores 11 and 21 have the same magnetic polarity.
  • the end faces 14 and 15 of the leg portions 12 and 13 of the first magnetic sensor 10 are shaped like circles with the same diameter.
  • the end faces 24 and 25 of the leg portions 22 and 23 of the second magnetic sensor 20 are shaped like circles with the same diameter (likewise but not shown).
  • FIG. 6 is a circuit diagram showing an embodiment of the metal disk discrimination apparatus according to the invention.
  • the coils 17 , 16 , 26 and 27 of the first and second magnetic sensors 10 and 20 are electrically connected in series in this order and are driven to be excited at a predetermined frequency by an oscillation circuit 200 .
  • the oscillation frequency of the oscillation circuit 200 is a frequency not allowing any electromagnetic field to permeate the metal disk 3 , and more specifically, it is preferable that the oscillation frequency is not lower than 100 kHz.
  • a demagnetizing field is emitted from the metal disk 3 to each coil to thereby disturb the magnetic field emitted from the coil, so that impedance of the coils changes to thereby cause change of electrical characteristics such as amplitude, frequency, etc. of an output voltage.
  • a detection circuit 201 detects an output waveform of the coils, and a rectification, amplification and filtering circuit 202 performs rectification, amplification and filtering on the output of the detection circuit 201 .
  • An AD conversion unit 203 converts the output of the rectification, amplification and filtering circuit 202 into a digital signal.
  • a comparison and determination unit 204 compares the digital signal with a predetermined reference value and outputs information for discriminating between genuineness and counterfeit of metal disks and between kinds of the metal disks based on the comparison.
  • the end faces 14 and 15 of the leg portions 12 and 13 of the magnetic sensor 10 are shaped like circles with the same diameter which is not larger than the diameter of the smallest one of the metal disks 3 as subjects of discrimination.
  • magnetic flux 42 flowing between the two leg portions 12 and 13 is concentrated into a narrow range to thereby increase magnetic flux density and narrow the range of the metal disk 3 affected by the magnetic flux 42 .
  • the surface shape of the metal disk 3 can be detected in such a narrow range with high sensitivity.
  • each of the end faces of the leg portions of the magnetic sensors is shaped like a rectangle to make the magnitude of leakage magnetic flux negligible compared with the magnitude of principal magnetic flux to thereby improve sensitivity in detection of an edge shape of a metal disk.
  • the rectangular shape of each end face expands the width of magnetic flux flow.
  • FIG. 8A shows the case where the end faces 14 and 15 of the leg portions of each magnetic sensor are shaped like rectangles.
  • FIG. 8B shows the case where the end faces 14 and 15 are shaped like squares.
  • FIG. 8C shows the case where the end faces 14 and 15 are shaped like circles.
  • a leg width d is common to the two leg portions which make a pair.
  • FIG. 10 shows the sensor output difference affected by the difference between the sensor shapes shown in FIGS. 8A , 8 B and 8 C. It is apparent from FIG. 10 that the detection sensitivity is lowered in the order of circle>square>rectangle according to the shape of each leg portion of the magnetic sensor. This is an instance showing that the circular shape improved in magnetic flux density can heighten the detection sensitivity compared with the square or rectangular shape expanded in magnetic flux width.
  • each of adjacent inner end faces of the two leg portions of each magnetic sensor is small in radius of curvature is preferred as the shape of each of the end faces of the leg portions of the magnetic sensors used in the metal disk discrimination apparatus according to the embodiment of the invention.
  • the radius of curvature of the adjacent inner end faces of the two leg portions of each magnetic sensor is not larger than the radius of the smallest one of the metal disks 3 .
  • an egg shape narrowed toward each of adjacent inner sides as shown in FIG. 11 a sector shape sharpened toward each of adjacent inner sides as shown in FIG. 12 , or a taper shape tapered toward each of adjacent inner sides as shown in FIG. 13 may be used as the shape of each of the end faces 14 and 15 of the leg portions of the magnetic sensor.
  • the two-legged core 11 may be shaped like such a U figure that the leg portions 12 and 13 are connected to each other by the connection portion 18 smoothly with a curved face as shown in FIG. 15 or may be shaped like such a H figure that the connection portion 18 protrudes from the leg portions 12 and 13 as shown in FIG. 16 .
  • any modification may be made as long as the metal disk 3 can be moved relative to the magnetic sensors 10 and 20 .
  • the magnetic sensors 10 and 20 may be moved in the condition that the metal disk 3 is fixed.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Coins (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
US12/361,706 2008-03-18 2009-01-29 Metal disk discrimination apparatus Abandoned US20090235733A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-069706 2008-03-18
JP2008069706A JP5242205B2 (ja) 2008-03-18 2008-03-18 金属円板判別装置

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110126618A1 (en) * 2009-07-16 2011-06-02 Blake Duane C AURA devices and methods for increasing rare coin value
US20120074959A1 (en) * 2011-02-01 2012-03-29 Pin-Chia Lee Coin detector
US10497198B2 (en) * 2017-04-10 2019-12-03 Douglas A. Pinnow Method and apparatus for discriminating gold and silver coins and bars from counterfeit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5609234A (en) * 1992-05-06 1997-03-11 Walker; Robert S. Coin validator
US6068102A (en) * 1996-11-27 2000-05-30 Canon Denshi Kabushiki Kaisha Coin identification device for identifying a coin on the basis of change in magnetic field due to eddy currents produced in the coin

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000187746A (ja) * 1998-12-22 2000-07-04 Canon Electronics Inc 硬貨選別装置
JP4143711B2 (ja) * 2000-08-30 2008-09-03 旭精工株式会社 コインセンサのコア

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5609234A (en) * 1992-05-06 1997-03-11 Walker; Robert S. Coin validator
US6068102A (en) * 1996-11-27 2000-05-30 Canon Denshi Kabushiki Kaisha Coin identification device for identifying a coin on the basis of change in magnetic field due to eddy currents produced in the coin

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110126618A1 (en) * 2009-07-16 2011-06-02 Blake Duane C AURA devices and methods for increasing rare coin value
US8661889B2 (en) 2009-07-16 2014-03-04 Duane C. Blake AURA devices and methods for increasing rare coin value
US20120074959A1 (en) * 2011-02-01 2012-03-29 Pin-Chia Lee Coin detector
US10497198B2 (en) * 2017-04-10 2019-12-03 Douglas A. Pinnow Method and apparatus for discriminating gold and silver coins and bars from counterfeit

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Publication number Publication date
JP2009223777A (ja) 2009-10-01
JP5242205B2 (ja) 2013-07-24

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Owner name: KABUSHIKI KAISHA TOSHIBA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HATO, TAKEHIRO;AKIBA, TOSHIKATSU;KOTANI, KAZUMI;REEL/FRAME:022173/0462;SIGNING DATES FROM 20090114 TO 20090120

Owner name: TOSHIBA TEC KABUSHIKI KAISHA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HATO, TAKEHIRO;AKIBA, TOSHIKATSU;KOTANI, KAZUMI;REEL/FRAME:022173/0462;SIGNING DATES FROM 20090114 TO 20090120

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION